Orthogonal frequency division multiple access resource request

ABSTRACT

A method for transmitting a resource request for an orthogonal frequency division multiple access (OFDMA) transmission is described. A resource request field that indicates buffer information corresponding to queued media access control (MAC) protocol data units (MPDUs) that are queued for transmission by a first communication device is generated. The resource request field includes i) a scale factor subfield that indicates a scale value, and ii) a resource subfield that indicates a base resource value. A resource request MPDU including the resource request field is generated. The resource request MPDU is transmitted to a second communication device via a wireless communication channel to request an allocation of radio resources for the OFDMA transmission. The buffer information is i) a number of bytes indicated by the scale value multiplied by the base resource value, or ii) a transmission opportunity duration indicated by the scale value multiplied by the base resource value.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/113,755, entitled “STA Resource Request,” filed onFeb. 9, 2015, and U.S. Provisional Patent Application No. 62/149,383,entitled “STA Resource Request,” filed on Apr. 17, 2015, the disclosuresof each of which are incorporated herein by reference in theirentireties.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to communication networks and,more particularly, to wireless local area networks that utilize requestsfor radio resources.

BACKGROUND

Wireless local area networks (WLANs) have evolved rapidly over the pastdecade. Development of WLAN standards such as the Institute forElectrical and Electronics Engineers (IEEE) 802.11a, 802.11b, 802.11g,and 802.11n Standards has improved single-user peak data throughput. Forexample, the IEEE 802.11b Standard specifies a single-user peakthroughput of 11 megabits per second (Mbps), the IEEE 802.11a and802.11g Standards specify a single-user peak throughput of 54 Mbps, theIEEE 802.11n Standard specifies a single-user peak throughput of 600Mbps, and the IEEE 802.11ac Standard specifies a single-user peakthroughput in the gigabits per second (Gbps) range. Future standardspromise to provide even greater throughputs, such as throughputs in thetens of Gbps range.

SUMMARY

In an embodiment, a method for transmitting a resource request for anorthogonal frequency division multiple access (OFDMA) transmissionincludes generating, by a first communication device, a resource requestfield that indicates buffer information corresponding to queued mediaaccess control (MAC) protocol data units (MPDUs) that are queued fortransmission by the first communication device. The resource requestfield includes i) a scale factor subfield that indicates a scale value,and ii) a resource subfield that indicates a base resource value. Themethod includes generating, by the first communication device, aresource request MPDU that includes the resource request field. Themethod also includes transmitting, by the first communication device,the resource request MPDU to a second communication device via awireless communication channel to request an allocation of radioresources for the OFDMA transmission by the second communication device.The buffer information is i) a number of bytes indicated by the scalevalue multiplied by the base resource value, or ii) a transmissionopportunity (TXOP) duration indicated by the scale value multiplied bythe base resource value.

In another embodiment, a first communication device that transmits aresource request for an orthogonal frequency division multiple access(OFDMA) transmission includes a network interface device having one ormore integrated circuits. The one or more integrated circuits areconfigured to generate a resource request field that indicates bufferinformation corresponding to queued media access control (MAC) protocoldata units (MPDUs) that are queued for transmission by the firstcommunication device. The resource request field including i) a scalefactor subfield that indicates a scale value, and ii) a resourcesubfield that indicates a base resource value. The one or moreintegrated circuits are configured to generate a resource request MPDUthat includes the resource request field. The one or more integratedcircuits are configured to transmit the resource request MPDU to asecond communication device via a wireless communication channel torequest an allocation of radio resources for the OFDMA transmission bythe second communication device. The buffer information is i) a numberof bytes indicated by the scale value multiplied by the base resourcevalue, or ii) a transmission opportunity (TXOP) duration indicated bythe scale value multiplied by the base resource value.

In an embodiment, a method for allocating radio resources for anorthogonal frequency division multiple access (OFDMA) transmissionincludes receiving, by a first communication device, a resource requestmedia access control (MAC) protocol data unit (MPDU) from a secondcommunication device. The resource request MPDU includes a resourcerequest field that indicates buffer information corresponding to queuedMPDUs that are queued for transmission by the second communicationdevice. The resource request field includes i) a scale factor subfieldthat indicates a scale value, and ii) a resource subfield that indicatesa base resource value. The method includes allocating, by the firstcommunication device, radio resources to the second communication devicefor the OFDMA transmission based on the scale value and the baseresource value. The method also includes generating, by the firstcommunication device, a scheduling MPDU that indicates the radioresources allocated to the second communication device. The methodincludes transmitting, by the first communication device, the schedulingMPDU to the second communication device via a wireless communicationchannel.

In another embodiment, a first communication device that allocates radioresources for an orthogonal frequency division multiple access (OFDMA)transmission includes a network interface device having one or moreintegrated circuits. The one or more integrated circuits are configuredto receive a resource request media access control (MAC) protocol dataunit (MPDU) from a second communication device. The resource requestMPDU includes a resource request field that indicates buffer informationcorresponding to queued MPDUs that are queued for transmission by thesecond communication device, the resource request field including i) ascale factor subfield that indicates a scale value, and ii) a resourcesubfield that indicates a base resource value. The one or moreintegrated circuits are configured to allocate radio resources to thesecond communication device for the OFDMA transmission based on thescale value and the base resource value. The one or more integratedcircuits are configured to generate a scheduling MPDU that indicates theradio resources allocated to the second communication device. The one ormore integrated circuits are configured to transmit the scheduling MPDUto the second communication device via a wireless communication channel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example wireless local area network(WLAN), according to an embodiment.

FIGS. 2A and 2B are diagrams of a prior art data unit format.

FIG. 3 is a diagram of another prior art data unit format.

FIG. 4 is a diagram of another prior art data unit format.

FIG. 5 is a diagram of another prior art data unit format.

FIG. 6 is a diagram of an example orthogonal frequency divisionmultiplexing (OFDM) data unit, according to an embodiment.

FIG. 7 is a diagram of an example medium access control (MAC) protocoldata unit (MPDU), according to an embodiment.

FIG. 8 is a diagram of an example MPDU that includes buffer informationfor a resource request, according to an embodiment.

FIG. 9A is a diagram of an example MPDU that includes buffer informationfor multiple resource requests, according to an embodiment.

FIG. 9B is a diagram of an example buffer information field of the MPDUof FIG. 9A, according to an embodiment.

FIG. 10 is a diagram of an example aggregate MPDU for a plurality ofresource requests, according to an embodiment.

FIG. 11 is a diagram of an example MPDU delimiter for an aggregate MPDU,according to an embodiment.

FIG. 12 is a diagram of an example MPDU that includes buffer informationin a high throughput (HT) control field, according to an embodiment.

FIG. 13 is a diagram of an example HT control middle subfield thatincludes buffer information, according to another embodiment.

FIG. 14 is a diagram of an example sequence of OFDM data units forproviding buffer information to an access point, according to anembodiment.

FIG. 15 is a diagram of an example sequence of OFDM data units forproviding buffer information and data to an access point, according toan embodiment.

FIG. 16 is a diagram of an example sequence of OFDM data units forproviding buffer information and an acknowledgment to an access point,according to an embodiment.

FIG. 17 is a diagram of an example sequence of an orthogonal frequencydivision multiple access (OFDMA) frame exchange for an access point thatrequests buffer information from multiple stations, according to anembodiment.

FIG. 18 is a diagram of an example sequence of OFDMA data units for anaccess point that requests buffer information from multiple stations,according to another embodiment.

FIG. 19 is a diagram of an example sequence of OFDMA data units for anaccess point that requests buffer information from multiple stations,according to yet another embodiment.

FIG. 20 is a diagram of an example sequence of OFDMA data units for anaccess point that requests buffer information from multiple stations,according to another embodiment.

FIG. 21 is a diagram of an example sequence of OFDMA data units for anaccess point that requests buffer information from multiple stations,according to another embodiment.

FIG. 22 is a diagram of an example sequence of OFDMA data units for abuffer information request utilizing separated polling, according to anembodiment.

FIG. 23 is a diagram of an example sequence of OFDMA data units for abuffer information request utilizing separated polling, according toanother embodiment.

FIG. 24 is a diagram of an example sequence of OFDMA data units for abuffer information request within a restricted access window, accordingto an embodiment.

FIG. 25 is a diagram of an example quality of service (QoS) controlfield of an MPDU that includes a scale factor for buffer information,according to an embodiment.

FIG. 26 is a diagram of an example MPDU that includes buffer informationfor a resource request, according to an embodiment.

FIG. 27 is a diagram of an example MPDU that includes buffer informationfor multiple resource requests, according to another embodiment.

FIG. 28 is a flow diagram of an example method for transmitting aresource request for an OFDMA transmission, according to an embodiment.

FIG. 29 is a flow diagram of an example method for allocating radioresources for an OFDMA transmission, according to an embodiment.

DETAILED DESCRIPTION

In embodiments described below, a wireless network device such as anaccess point (AP) or client station (STA) of a wireless local areanetwork (WLAN) generates an orthogonal frequency division multiplex(OFDM) data unit having a media access control (MAC) protocol data unit(MPDU) that includes resource request information. In an embodiment, forexample, the client station generates a resource request frame (e.g.,resource request MPDU). In some embodiments and/or scenarios, an AP orSTA transmits or receives an MPDU of an orthogonal frequency divisionmultiple access (OFDMA) data unit via an OFDM communication channel. Ingeneral, an AP or other network device allocates or assigns radioresources of an OFDM communication channel to specific STAs or groups ofSTAs for data transfers using OFDMA. For example, the AP makes anallocation of one or more tones, tone blocks, or sub-channels of theOFDM communication channel to multiple STAs. In an embodiment, the APtransmits to the STAs a resource allocation message that indicates theallocation to each of the STAs. During a subsequent OFDMA data transfer,each of the STAs simultaneously transmits an OFDM data unit using itsallocated sub-channels. Although the description herein is generallybased on embodiments and scenarios utilizing OFDMA, the methods andtechniques described are utilized with multi-user multiple input,multiple output (MU-MIMO) configurations where different client stationsuse different spatial streams to transmit and/or receive frames, invarious embodiments and/or scenarios.

In some embodiments and/or scenarios, the resource request frameindicates buffer information corresponding to frames of the STA that arequeued for transmission. In other embodiments and/or scenarios, theresource request frame indicates buffer information corresponding to atransmission opportunity (TXOP) having an indicated duration. In someembodiments, the resource request frame includes a scale factor for thebuffer information to provide an increased range of available values forthe buffer information and thus improved accuracy of resource requests.

FIG. 1 is a block diagram of an example wireless local area network(WLAN) 10, according to an embodiment. An AP 14 includes a hostprocessor 15 coupled to a network interface 16. In an embodiment, thenetwork interface 16 includes one or more integrate circuits (ICs)configured to operate as discussed below. The network interface 16includes a medium access control (MAC) processor 18 and a physical layer(PHY) processor 20. The PHY processor 20 includes a plurality oftransceivers 21, and the transceivers 21 are coupled to a plurality ofantennas 24. Although three transceivers 21 and three antennas 24 areillustrated in FIG. 1, the AP 14 includes other suitable numbers (e.g.,1, 2, 4, 5, etc.) of transceivers 21 and antennas 24 in otherembodiments. In some embodiments, the AP 14 includes a higher number ofantennas 24 than transceivers 21, and antenna switching techniques areutilized. In an embodiment, the MAC processor 18 is implemented on atleast a first IC, and the PHY processor 20 is implemented on at least asecond IC. In an embodiment, at least a portion of the MAC processor 18and at least a portion of the PHY processor 20 are implemented on asingle IC.

In an embodiment, the PHY processor 20 scrambles an MPDU (e.g., a PHYservice data unit) based on a scramble seed.

In various embodiments, the MAC processor 18 and the PHY processor 20are configured to operate according to a first communication protocol(e.g., a High Efficiency, HE, or 802.11ax communication protocol). Insome embodiments, the MAC processor 18 and the PHY processor 20 are alsoconfigured to operate according to a second communication protocol(e.g., according to the IEEE 802.11ac Standard). In yet anotherembodiment, the MAC processor 18 and the PHY processor 20 areadditionally configured to operate according to the second communicationprotocol, a third communication protocol, and/or a fourth communicationprotocol (e.g., according to the IEEE 802.11a Standard and/or the IEEE802.11n Standard).

The WLAN 10 includes a plurality of client stations 25. Although fourclient stations 25 are illustrated in FIG. 1, the WLAN 10 includes othersuitable numbers (e.g., 1, 2, 3, 5, 6, etc.) of client stations 25 invarious scenarios and embodiments. At least one of the client stations25 (e.g., client station 25-1) is configured to operate at leastaccording to the first communication protocol. In some embodiments, atleast one of the client stations 25 is not configured to operateaccording to the first communication protocol but is configured tooperate according to at least one of the second communication protocol,the third communication protocol, and/or the fourth communicationprotocol (referred to herein as a “legacy client station”).

The client station 25-1 includes a host processor 26 coupled to anetwork interface 27. In an embodiment, the network interface 27includes one or more ICs configured to operate as discussed below. Thenetwork interface 27 includes a MAC processor 28 and a PHY processor 29.The PHY processor 29 includes a plurality of transceivers 30, and thetransceivers 30 are coupled to a plurality of antennas 34. Althoughthree transceivers 30 and three antennas 34 are illustrated in FIG. 1,the client station 25-1 includes other suitable numbers (e.g., 1, 2, 4,5, etc.) of transceivers 30 and antennas 34 in other embodiments. Insome embodiments, the client station 25-1 includes a higher number ofantennas 34 than transceivers 30, and antenna switching techniques areutilized. In an embodiment, the MAC processor 28 is implemented on atleast a first IC, and the PHY processor 29 is implemented on at least asecond IC. In an embodiment, at least a portion of the MAC processor 28and at least a portion of the PHY processor 29 are implemented on asingle IC.

According to an embodiment, the client station 25-4 is a legacy clientstation, i.e., the client station 25-4 is not enabled to receive andfully decode a data unit that is transmitted by the AP 14 or anotherclient station 25 according to the first communication protocol.Similarly, according to an embodiment, the legacy client station 25-4 isnot enabled to transmit data units according to the first communicationprotocol. On the other hand, the legacy client station 25-4 is enabledto receive and fully decode and transmit data units according to thesecond communication protocol, the third communication protocol, and/orthe fourth communication protocol.

In an embodiment, one or both of the client stations 25-2 and 25-3, hasa structure that is the same as or similar to the client station 25-1.In an embodiment, the client station 25-4 has a structure similar to theclient station 25-1. In these embodiments, the client stations 25structured the same as or similar to the client station 25-1 have thesame or a different number of transceivers and antennas. For example,the client station 25-2 has only two transceivers and two antennas (notshown), according to an embodiment.

In various embodiments, the MAC processor 18 and the PHY processor 20 ofthe AP 14 are configured to generate data units conforming to the firstcommunication protocol and having formats described herein. In anembodiment, the MAC processor 18 is configured to implement MAC layerfunctions, including MAC layer functions of the first communicationprotocol. In an embodiment, the PHY processor 20 is configured toimplement PHY functions, including PHY functions of the firstcommunication protocol. For example, in an embodiment, the MAC processor18 is configured to generate MAC layer data units such as MPDUs, MACcontrol frames, etc., and provide the MAC layer data units to the PHYprocessor 20. In an embodiment, the PHY processor 20 is configured toreceive MAC layer data units from the MAC processor 18 and encapsulatethe MAC layer data units to generate PHY data units such as PHY protocoldata units (PPDUs) for transmission via the antennas 24. Similarly, inan embodiment, the PHY processor 20 is configured to receive PHY dataunits that were received via the antennas 24, and extract MAC layer dataunits encapsulated within the PHY data units. In an embodiment, the PHYprocessor 20 provides the extracted MAC layer data units to the MACprocessor 18, which processes the MAC layer data units.

The transceiver(s) 21 is/are configured to transmit the generated dataunits via the antenna(s) 24. Similarly, the transceiver(s) 21 is/areconfigured to receive data units via the antenna(s) 24. The MACprocessor 18 and the PHY processor 20 of the AP 14 are configured toprocess received data units conforming to the first communicationprotocol and having formats described hereinafter and to determine thatsuch data units conform to the first communication protocol, accordingto various embodiments.

In various embodiments, the MAC processor 28 and the PHY processor 29 ofthe client device 25-1 are configured to generate data units conformingto the first communication protocol and having formats described herein.In an embodiment, the MAC processor 28 is configured to implement MAClayer functions, including MAC layer functions of the firstcommunication protocol. In an embodiment, the PHY processor 29 isconfigured to implement PHY functions, including PHY functions of thefirst communication protocol. For example, in an embodiment, the MACprocessor 28 is configured to generate MAC layer data units such asMPDUs, MAC control frames, etc., and provide the MAC layer data units tothe PHY processor 29. In an embodiment, the PHY processor 29 isconfigured to receive MAC layer data units from the MAC processor 28 andencapsulate the MAC layer data units to generate PHY data units such asPPDUs for transmission via the antennas 34. Similarly, in an embodiment,the PHY processor 29 is configured to receive PHY data units that werereceived via the antennas 34, and extract MAC layer data unitsencapsulated within the PHY data units. In an embodiment, the PHYprocessor 29 provides the extracted MAC layer data units to the MACprocessor 28, which processes the MAC layer data units.

The transceiver(s) 30 is/are configured to transmit the generated dataunits via the antenna(s) 34. Similarly, the transceiver(s) 30 is/areconfigured to receive data units via the antenna(s) 34. The MACprocessor 28 and the PHY processor 29 of the client device 25-1 areconfigured to process received data units conforming to the firstcommunication protocol and having formats described hereinafter and todetermine that such data units conform to the first communicationprotocol, according to various embodiments.

In various embodiments, one or both of the AP 14 and the client device25-1 are configured to receive OFDM data units that include reducedlength MPDUs. In an embodiment, for example, the AP 14 maintains anassociation of a client station with an allocated sub-channel of theOFDM communication channel such that the AP 14 can generally identifywhich client station has transmitted an OFDM data unit based on thesub-channel on which the OFDM data unit was received. In anotherembodiment, the client station 25-1 maintains an association of the AP14 with the allocated sub-channel such that the client station 25-1 cangenerally identify which AP has transmitted an OFDM data unit based onthe sub-channel on which the OFDM data unit was received.

FIG. 2A is a diagram of a prior art orthogonal frequency divisionmultiplexing (OFDM) data unit 200 that the AP 14 is configured totransmit to the legacy client station 25-4 via orthogonal frequencydivision multiplexing (OFDM) modulation, according to an embodiment. Inan embodiment, the legacy client station 25-4 is also configured totransmit the data unit 200 to the AP 14. The data unit 200 conforms tothe IEEE 802.11a Standard and occupies a 20 Megahertz (MHz) bandwidth.The data unit 200 includes a preamble having a legacy short trainingfield (L-STF) 202, generally used for packet detection, initialsynchronization, and automatic gain control, etc., and a legacy longtraining field (L-LTF) 204, generally used for channel estimation andfine synchronization. The data unit 200 also includes a legacy signalfield (L-SIG) 206, used to carry certain physical layer (PHY) parameterswith the data unit 200, such as modulation type and coding rate used totransmit the data unit, for example. The data unit 200 also includes adata portion 208. FIG. 2B is a diagram of example data portion 208 (notlow density parity check encoded), which includes a service field, ascrambled physical layer service data unit (PSDU), tail bits, andpadding bits, if needed. The data unit 200 is designed for transmissionover one spatial or space-time stream in a single input single output(SISO) channel configuration. In various embodiments, the data portion208 includes a MAC protocol data unit (MPDU).

FIG. 3 is a diagram of a prior art OFDM data unit 300 that the AP 14 isconfigured to transmit to the legacy client station 25-4 via OFDMmodulation, according to an embodiment. In an embodiment, the legacyclient station 25-4 is also configured to transmit the data unit 300 tothe AP 14. The data unit 300 conforms to the IEEE 802.11n Standard,occupies a 20 MHz or 40 MHz bandwidth, and is designed for mixed modesituations, i.e., when the WLAN includes one or more client stationsthat conform to the IEEE 802.11a Standard but not the IEEE 802.11nStandard. The data unit 300 includes a preamble having an L-STF 302, anL-LTF 304, an L-SIG 306, a high throughput signal field (HT-SIG) 308, ahigh throughput short training field (HT-STF) 310, and M data highthroughput long training fields (HT-LTFs) 312, where M is an integergenerally based on the number of spatial streams used to transmit thedata unit 300 in a multiple input multiple output (MIMO) channelconfiguration. In particular, according to the IEEE 802.11n Standard,the data unit 300 includes two HT-LTFs 312 if the data unit 300 istransmitted using two spatial streams, and four HT-LTFs 312 is the dataunit 300 is transmitted using three or four spatial streams. Anindication of the particular number of spatial streams being utilized isincluded in the HT-SIG field 308. The data unit 300 also includes a dataportion 314. In various embodiments, the data portion 314 includes anMPDU.

FIG. 4 is a diagram of a prior art OFDM data unit 400 that the AP 14 isconfigured to transmit to the legacy client station 25-4 via OFDMmodulation, according to an embodiment. In an embodiment, the legacyclient station 25-4 is also configured to transmit the data unit 400 tothe AP 14. The data unit 400 conforms to the IEEE 802.11n Standard,occupies a 20 MHz or MHz bandwidth, and is designed for “Greenfield”situations, i.e., when the WLAN does not include any client stationsthat conform to the IEEE 802.11a Standard, and only includes clientstations that conform to the IEEE 802.11n Standard. The data unit 400includes a preamble having a high throughput Greenfield short trainingfield (HT-GF-STF) 402, a first high throughput long training field(HT-LTF1) 404, a HT-SIG 406, and M data HT-LTFs 408. The data unit 400also includes a data portion 410. In various embodiments, the dataportion 410 includes an MPDU.

FIG. 5 is a diagram of a prior art OFDM data unit 500 that the AP 14 isconfigured to transmit to the legacy client station 25-4 via OFDMmodulation, according to an embodiment. In an embodiment, the legacyclient station 25-4 is also configured to transmit the data unit 500 tothe AP 14. The data unit 500 is designed for “Mixed field” situationsand conforms to the IEEE Standard for Information Technology, Part 11:Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)Specifications, Amendment 4: Enhancements for Very High Throughput forOperations in Bands below 6 GHz, 2013 (“the IEEE 802.11ac standard”),the disclosure of which is incorporated herein by reference in itsentirety. The data unit 500 occupies a 20 MHz bandwidth. In otherembodiments or scenarios, a data unit similar to the data unit 500occupies a different suitable bandwidth, such as a 40 MHz, an 80 MHz, ora 160/80+80 MHz bandwidth. The data unit 500 includes a preamble havingan L-STF 502, an L-LTF 504, an L-SIG 506, two first very high throughputsignal fields (VHT-SIGAs) 508 including a first very high throughputsignal field (VHT-SIGA1) 508-1 and a second very high throughput signalfield (VHT-SIGA2) 508-2, a very high throughput short training field(VHT-STF) 510, M very high throughput long training fields (VHT-LTFs)512, and a second very high throughput signal field (VHT-SIG-B) 514. Thedata unit 500 also includes a data portion 516. In various embodiments,the data portion 516 includes an MPDU.

In an embodiment, the data unit 500 occupies a bandwidth that is aninteger multiple of 20 MHz and the L-STF 502 is duplicated within each20 MHz sub-band. In an embodiment, the VHT-STF 510 has a duration of 4.0microseconds and uses a same frequency sequence as the L-STF 502. Forexample, in an embodiment, the VHT-STF 510 uses the frequency sequencedefined in equation 22-29 of the IEEE 802.11ac standard. In at leastsome embodiments, the VHT-STF 510 occupies a whole bandwidth for thedata unit 500 (e.g., 20 MHz, 40 MHz, 80 MHz, etc.) and is mapped tomultiple antennas for multiple input, multiple output (MIMO) orbeamforming in a manner similar to the data portion 516.

FIG. 6 is a diagram of an OFDM data unit 600 that the AP 14 isconfigured to transmit to the client station 25-1 via orthogonalfrequency domain multiplexing (OFDM) modulation, according to anembodiment. In an embodiment, the client station 25-1 is also configuredto transmit the data unit 600 to the AP 14. The data unit 600 conformsto the first communication protocol and occupies a 20 MHz bandwidth.Data units that conform to the first communication protocol similar tothe data unit 600 may occupy other suitable bandwidths such as 40 MHz,80 MHz, 160 MHz, 320 MHz, 640 MHz, etc., for example, or other suitablebandwidths, in other embodiments. The data unit 600 is suitable for“mixed mode” situations, i.e., when the WLAN 10 includes a clientstation (e.g., the legacy client station 25-4) that conforms to a legacycommunication protocol, but not the first communication protocol. Thedata unit 600 is utilized in other situations as well, in someembodiments.

In an embodiment, the data unit 600 includes a preamble 601 having anL-STF 602, an L-LTF 604, an L-SIG 606, two first HE signal fields(HE-SIGAs) 608 including a first HE signal field (HE-SIGA1) 608-1 and asecond HE signal field (HE-SIGA2) 608-2, a HE short training field(HE-STF) 610, an integer number M HE long training fields (HE-LTFs) 612,and a third HE signal field (HE-SIGB) 614. In an embodiment, thepreamble 601 includes a legacy portion 601-1, including the L-STF 602,the L-LTF 604, and the L-SIG 606, and a non-legacy portion 601-2,including the HE-SIGAs 608, HE-STF 610, M HE-LTFs 612, and HE-SIGB 614.

Each of the L-STF 602, the L-LTF 604, the L-SIG 606, the HE-SIGAs 608,the HE-STF 610, the M HE-LTFs 612, and the HE-SIGB 614 are included inan integer number of one or more OFDM symbols. For example, in anembodiment, the HE-SIGAs 608 correspond to two OFDM symbols, where theHE-SIGA1 608-1 field is included in the first OFDM symbol and theHE-SIGA2 is included in the second OFDM symbol. In another embodiment,for example, the preamble 601 includes a third HE signal field(HE-SIGA3, not shown) and the HE-SIGAs 608 correspond to three OFDMsymbols, where the HE-SIGA1 608-1 field is included in the first OFDMsymbol, the HE-SIGA2 is included in the second OFDM symbol, and theHE-SIGA3 is included in the third OFDM symbol. In at least someexamples, the HE-SIGAs 608 are collectively referred to as a single HEsignal field (HE-SIGA) 608. In some embodiments, the data unit 600 alsoincludes a data portion 616. In other embodiments, the data unit 600omits the data portion 616 (e.g., the data unit 600 is a null-dataframe).

In the embodiment of FIG. 6, the data unit 600 includes one of each ofthe L-STF 602, the L-LTF 604, the L-SIG 606, and the HE-SIGA Is 608. Inother embodiments in which an OFDM data unit similar to the data unit600 occupies a cumulative bandwidth other than 20 MHz, each of the L-STF602, the L-LTF 604, the L-SIG 606, the HE-SIGA1s 608 is repeated over acorresponding number of 20 MHz-wide sub-bands of the whole bandwidth ofthe data unit, in an embodiment. For example, in an embodiment, the OFDMdata unit occupies an 80 MHz bandwidth and, accordingly, includes fourof each of the L-STF 602, the L-LTF 604, the L-SIG 606, and theHE-SIGA1s 608 in four 20 MHz-wide sub-bands that cumulatively span the80 MHz bandwidth, in an embodiment. In some embodiments, the modulationof different 20 MHz-wide sub-bands signals is rotated by differentangles. For example, in one embodiment, a first sub-band is rotated0-degrees, a second sub-band is rotated 90-degrees, a third sub-band isrotated 180-degrees, and a fourth sub-band is rotated 270-degrees. Inother embodiments, different suitable rotations are utilized. Thedifferent phases of the 20 MHz-wide sub-band signals result in reducedpeak to average power ratio (PAPR) of OFDM symbols in the data unit 600,in at least some embodiments. In an embodiment, if the data unit thatconforms to the first communication protocol is an OFDM data unit thatoccupies a cumulative bandwidth such as 20 MHz, 40 MHz, 80 MHz, 160 MHz,320 MHz, 640 MHz, etc., the HE-STF, the HE-LTFs, the HE-SIGB and the HEdata portion occupy the corresponding whole bandwidth of the data unit.

FIG. 7 is a diagram of an MPDU 700, according to an embodiment. The MPDU700 includes a MAC header 702, a frame body 718, and a frame checksequence field 720. The MPDU 700 generally conforms to the IEEE Standardfor Information Technology, Part 11: Wireless LAN Medium Access Control(MAC) and Physical Layer (PHY) Specifications, 2012 (“the IEEE802.11-2012 standard”), the disclosure of which is incorporated hereinby reference in its entirety. The number above each field in FIG. 7indicates the number of octets occupied by the corresponding field.Accordingly, the MAC header 702 includes a frame control field 704 (2octets), a duration/ID field 706 (2 octets), a first address (A1) field710-1 (6 octets), a second address (A2) field 710-2 (6 octets), a thirdaddress (A3) field (6 octets) 710-3, a sequence control field 712 (2octets), a fourth address (A4) field 710-4 (6 octets), a QoS controlfield 714 (2 octets), and an HT control field 716 (4 octets). The MPDU700 also includes the frame body 718 and the four-octet frame checksequence (FCS) field 720. In some embodiments and/or scenarios, theframe body 718 is omitted (e.g., a null data frame). Each of the addressfields 710 is a 48 bit (6 octet) field that includes a globally uniqueMAC address of a device associated with the data unit 700, such as atransmitting device of the data unit 700, a receiving device of the dataunit 700, etc. In general, the MAC header 702 occupies 36 octets of theMPDU 700.

FIG. 8 is a diagram of an MPDU 800 that includes buffer information fora resource request, according to another embodiment. The MPDU 800includes a MAC header 802, a frame body 816, and a frame check sequence(FCS) field 818. The number above each field of the MPDU 800 in FIG. 8indicates the number of octets occupied by the corresponding field.Accordingly, the MAC header 802 includes a frame control field 804 (2octets), a first address (A1) field 810-1 (6 octets), a second address(A2) field 810-2 (6 octets), a duration field (2 octets) 812, and aresource request field 814 (2 octets), in an embodiment. In someembodiments and/or scenarios, the frame body 816 is omitted (e.g., anull data frame).

In some embodiments and/or scenarios (not shown), the MAC header 802 hasa “short frame format” having a reduced length of the MAC header 802. Inan embodiment, the MPDU 800 is similar to “short frames” as described inthe IEEE 802.11ah protocol. In some embodiments and/or scenarios, one ormore of the address fields 810-1 or 810-2 is a 48 bit (6 octet) fieldthat includes a globally unique MAC address of a device associated withthe data unit 800, such as a transmitting device of the data unit 800, areceiving device of the data unit 800, etc. In other embodiments and/orscenarios, one or more of the address fields 810-1 or 810-2 is a 16 bit(2 octet) field that includes a BSS color identifier, partialassociation identification (PAID or partial AID), or other suitableaddress having a reduced length as compared to a MAC address (i.e., lessthan 6 octets). In various embodiments, the BSS color identifieroccupies 6 bits, 7 bits, 10 bits, or another suitable number of bits.

In various embodiments, the resource request field 814 indicates bufferinformation corresponding to queued MPDUs that are queued fortransmission, in an embodiment. For example, the buffer informationindicates a TXOP duration that the client station 25 estimates is neededfor transmission of the queued MPDUs or a number of bytes for the queuedMPDUs. The buffer information from the client station 25 allows the APto determine one or more parameters for uplink OFDMA resourceallocation, for example, OFDMA physical layer convergence protocol(PLCP) protocol data unit (PPDU) length, channel position, channelbandwidth, modulation and control scheme, transmission power, or othersuitable parameters. In some scenarios, the client station 25 utilizesthe QoS control field 714 to provide buffer information; however, theQoS control field as described in the IEEE 802.11-2012 standard cannotreadily describe a number of bytes less than 256 bytes or higher than64,768 bytes in increments of 256 octets and cannot describe a TXOPduration less than 32 microseconds or higher than 8,160 microseconds inincrements of 32 microseconds.

In the embodiment shown in FIG. 8, the resource request field 814includes i) a scale factor subfield 822 that indicates a scale value,and ii) a resource subfield 824 (or buffer information indication) thatindicates a base resource value. The scale value multiplied by the baseresource value indicates buffer information with improved accuracy ascompared to the QoS control field of the IEEE 802.11-2012 standard. Insome embodiments and/or scenarios, the buffer information indicated bythe resource request field 814 is a number of bytes equal to the scalevalue of the scale factor subfield 822 multiplied by the base resourcevalue of the resource subfield 824. In other embodiments and/orscenarios, the buffer information indicated by the resource requestsubfield 814 is a transmission opportunity (TXOP) duration indicated bythe scale value multiplied by the base resource value. In someembodiments, the resource request field 814 includes a request typesubfield (not shown) that indicates whether the buffer informationindicates the number of bytes or the TXOP duration. In an embodiment,for example, a reserved bit of the frame control field 804 indicateswhether the buffer information indicates the number of bytes or the TXOPduration.

The number below the fields 820, 822, and 824 of the MPDU 800 in FIG. 8indicates the number of bits occupied by the corresponding field. Thescale factor field 822 has one bit that indicates a scale value orincrement value. In an embodiment, a value of “0” for the scale factorfield 822 corresponds to a scale value of one byte while a value of “1”corresponds to a scale value of 256 bytes. In other embodiments, thevalue of “0” for the scale factor field 822 corresponds to a scale valueof two bytes, three bytes, eight bytes, or another suitable value whilethe value of “1” corresponds to a scale value of 16 bytes, 32 bytes, 512bytes, or another suitable value. Accordingly, the 14 bits of theresource subfield 824 provide a base resource value that, whenmultiplied with the scale value, provide buffer information withimproved accuracy. In another embodiment, a value of “0” for the scalefactor field 822 corresponds to a scale value of one microsecond while avalue of “1” corresponds to a scale value of 16 microseconds. In otherembodiments, the value of “0” for the scale factor field 822 correspondsto a scale value of two microseconds, four microseconds, 16microseconds, or another suitable value while the value of “1”corresponds to a scale value of 32 microseconds, 64 microseconds, oranother suitable value.

The MPDU 800 is a resource request MPDU in that the resource requestfield 814 provides buffer information to a receiving device (e.g., anaccess point). In some embodiments, the client station 25 omits theframe body 816 from the resource request MPDU, in a manner similar to aQoS null frame. In other embodiments and/or scenarios, the resourcerequest MPDU wraps another MPDU or a portion of another MPDU (e.g., awrapped frame) within the frame body 816. In the embodiment shown inFIG. 8, the resource request field 814 also includes a wrapper subfield820. The wrapper subfield 820 indicates whether a wrapped MPDU isincluded in the resource request MPDU. In an embodiment, for example, avalue of “1” within the wrapper subfield 820 indicates that a wrappedframe is present, while a value of “0” within the wrapper subfield 820indicates that a wrapped frame is not present (i.e., the frame body 816is omitted). In an embodiment, the client station 25 generates the framecheck sequence field 818 based on the wrapped frame when present withinthe frame body 816. In some embodiments, the AP or client station 25omits an A-MPDU delimiter between the frames, a frame check sequencefield for the second frame, or both the A-MPDU and frame check sequencefield since a second frame is wrapped with the first frame.

In an embodiment, the wrapped frame shares at least some of theparameters provided within the MAC header 802, for example, the firstaddress field 810-1, the second address field 810-2, and the durationfield 812. In some embodiments, one or more parameters that aredifferent from the resource request MPDU are included within the framebody 816. In the embodiment shown in FIG. 8, the frame body 816 includesi) a wrapped type subfield 830 that indicates a frame type of thewrapped MPDU, and ii) a wrapped payload subfield 832 that includes apayload for the wrapped MPDU (e.g., frame content for the wrapped MPDU).In some embodiments, wrapped type subfield 830 indicates a type andsub-type of the wrapped MPDU. In an embodiment, the type and sub-type ofthe wrapped MPDU may be different from that of the resource requestMPDU. For example, the resource request MPDU may have a type andsub-type corresponding to a QoS Null data frame, while the wrapped MPDUmay have a type and sub-type corresponding to a clear to send controlframe, a Data+CF-Ack data frame, or other suitable control frames,management frames, or data frames.

In the embodiment shown in FIG. 8, the first address field 810-1 and thesecond address field 810-2 are the receiver address and transmitteraddress for the MPDU 800. In some embodiments and/or scenarios, theclient station 25 generates and transmits the MPDU 800 in response to apolling frame from the access point. In an embodiment, the clientstation 25 omits the second address field 810-2 (transmitter address)when transmitting in response to the polling frame. In one suchembodiment, the access point determines which client station 25transmitted the MPDU 800 based on an OFDM sub-channel on which the MPDU800 was received.

FIG. 9A is a diagram of an MPDU 900 that includes buffer information formultiple resource requests, according to an embodiment. The MPDU 900 isgenerally similar to the MPDU 800, but a resource request field 902replaces the resource request field 814. The resource request field 902provides buffer information for multiple data groups by utilizing abitmap subfield 904 and one or more resource subfields, such as theresource subfield 906. In an embodiment, the bitmap subfield 904indicates which data groups of a plurality of data groups correspond toa resource subfield included in the resource request field 902. Forexample, the bitmap subfield 904 includes a bit for each of theplurality of data groups.

In an embodiment, each of the one or more resource subfields includesinstances of a wrapper subfield 908, a scale factor 910, and a baseresource value field 912 for the corresponding data group. In anembodiment, each of the one or more resource subfields also includes arequest type subfield (not shown) that indicates whether the bufferinformation for the corresponding data group indicates the number ofbytes or the TXOP duration. In some embodiments, the wrapper indication908 and the frame body 816 are omitted. In other embodiments, thewrapper indication 908 indicates whether a portion of the frame body 816(i.e., an instance of the wrapped type subfield 830 and wrapped payload832) are included within the frame body 816 for the corresponding datagroup.

In the embodiment shown in FIG. 9A, the bitmap subfield 904 has eightbits corresponding to eight data groups where the data groups aretraffic classes. Accordingly, the MPDU 900 includes up to eightinstances of the resource subfield 906. In other embodiments, the bitmapsubfield 904 has six bits, seven bits, nine bits, ten bits, or anothersuitable number of bits. In an embodiment, the bitmap subfield 904 haseight bits, at least a portion of which are reserved or unused bits. Forexample, the bitmap subfield 904 includes four reserved bits and fourbits corresponding to four data groups where the data groups are accesscategories. In an embodiment, a reserved bit of the frame control field804 indicates whether the buffer information corresponds to trafficclasses or access categories. In some embodiments and/or scenarios, thebuffer information corresponds to a total number of queued MPDUs for aplurality of data groups. In an embodiment, for example, the clientstation 25 has 512 bytes, 384 bytes, and 128 bytes of queued MPDUs fortraffic classes having a TID of 0, 3, and 5, respectively, and thebuffer information indicates 1024 bytes (a sum total of 512, 384, and128 bytes). In an embodiment, a reserved bit of the frame control field804 indicates whether the buffer information corresponds to trafficclasses, access categories, or a total number of queued MPDUs.

FIG. 9B is a diagram of a buffer information field 950, for example, aninstance of the buffer information field 902 of FIG. 9A, according to anembodiment. In the illustrated embodiment, the buffer information field950 includes the bitmap subfield 904 having a value of “00100001,” whichindicates that buffer information for traffic classes corresponding toTID 0 and TID 5 are included within the buffer information field 950.Accordingly, the buffer information field 950 includes a resourcesubfield 906-1 (e.g., for TID 0) and a resource subfield 906-2 (e.g.,for TID 5).

FIG. 10 is a diagram of an aggregate MPDU (A-MPDU) 1000 for a pluralityof resource requests, according to an embodiment. The client station 25generates the A-MPDU 1000 that includes an MPDU for each of theplurality of resource requests, for example, a plurality of the MPDUs800. The A-MPDU 1000 includes an MPDU delimiter 1002, an MPDU 1004, andpadding 1006 for each included MPDU. In an embodiment, each MPDU of theA-MPDU 1000 is a QoS null MPDU. In the embodiment shown in FIG. 10, theA-MPDU 1000 includes the MPDU 1004-1 and MPDU 1004-2, each of which is aQoS null MPDU. The QoS null MPDU 1004-1 corresponds to a first datagroup and the QoS null MPDU 1004-2 corresponds to a second data groupthat is different from the first data group, in an embodiment. In anembodiment, the access point generates and transmits a singleacknowledgment frame to acknowledge a received A-MPDU 1000 if at leastone of the MPDUs 1004 is correctly received. In some embodiments, theA-MPDU 1000 includes one or more other MPDUs, for example, data MPDUs,control MPDUs, or other suitable MPDUs. FIG. 11 is a diagram of an MPDUdelimiter 1100 for an aggregate MPDU, such as the A-MPDU 1000, accordingto an embodiment. The MPDU delimiter 1100 includes an end of framesubfield 1102, a reserved subfield 1104, an MPDU length subfield 1106, acyclic redundancy check (CRC) field 1108, and a delimiter signature1110. In the embodiment of FIG. 10, each MPDU delimiter 1002 indicatesan end of frame value of zero and an MPDU length that is not equal tozero.

FIG. 12 is a diagram of an MPDU 1200 that includes buffer information ina high throughput (HT) control field, according to an embodiment. TheMPDU 1200 is generally similar to the MPDU 700 and includes similarfields as shown, but an HT control field 1216 replaces the HT controlfield 716. In various embodiments and/or scenarios, the MPDU 1200 is adata frame, control frame, management frame, or other suitable framethat repurposes the HT control field 1216 to include buffer informationfor a resource request. In various embodiments, the HT Control field isan HT variant HT Control field or a VHT variant HT Control field. In anembodiment, a reserved bit in the VHT variant HT Control field is set toa value of 1 (or other suitable value) to indicate that the HT Controlfield indicates buffer information. Similarly, in another embodiment, areserved bit in the HT variant HT Control field is set to a value of 1(or other suitable value) to indicate that the HT Control fieldindicates buffer information. In one embodiment, the HT control field1216 includes a very high throughput (VHT) indicator subfield 1222 (1bit), an HT control middle subfield 1224 (29 bits), and a resourcerequest subfield 1226 (2 bits).

The VHT indicator subfield 1222 indicates whether the format of the HTcontrol field 1216 is based on an HT format or on an VHT format, asdescribed in IEEE 802.11ac, Section 8.2.4.6 HT Control field. In theembodiment shown in FIG. 12, the VHT indicator subfield 1222 has a valueof zero, which indicates that the format of the HT control field 1216 isbased on the HT format, i.e. HT variant HT Control field (IEEE 802.11ac,Section 8.2.4.6.2 HT variant). Accordingly, the HT control middlesubfield 1224 includes a resource request subfield 1232 (19 bits), aresource request indicator 1234 (1 bit), and a resource request subfield1236 (9 bits). The resource request indicator 1234, located at bit 20 ofthe HT control field 1216, corresponds to a reserved subfield of the HTcontrol middle subfield of the HT format and indicates whether the HTcontrol field 1216 indicates resource request information or HT variantControl information. In an embodiment, for example, a value of “1” inthe resource request indicator 1234 indicates that the HT Control fieldincludes the resource request subfields 1226, 1232, and 1236 for aresource request, while a value of “0” indicates that the HT Controlfield includes HT variant HT Control information.

FIG. 13 is a diagram of an HT control middle subfield 1300 that includesbuffer information for the HT control field 1216, according to anotherembodiment. In the embodiment shown in FIG. 13, the VHT indicatorsubfield 1222 has a value of one, which indicates that the format of theHT control field 1216 is based on the VHT format, i.e. VHT variant HTControl (IEEE 802.11ac, Section 8.2.4.6.3 VHT variant). Accordingly, theHT control middle subfield 1224 includes a resource request indicator1334 (1 bit) and resource request subfield 1336 (28 bits). The resourcerequest indicator 1334, located at bit 1 of the HT control field 1216,corresponds to a reserved subfield of the HT control middle subfield ofthe VHT format and indicates whether the HT control field 1216 indicatesresource request information or VHT variant HT Control information.

FIG. 14 is a diagram of a sequence 1400 of OFDM data units for providingbuffer information to an access point, according to an embodiment. Inthe sequence 1400, a client station 25 generates a resource request MPDU1402. In an embodiment, the resource request MPDU 1402 is similar to theMPDU 800 or MPDU 900. In the embodiment shown in FIG. 14, the clientstation 25 omits the frame body 816 from the resource request MPDU 1402.In an embodiment, the client station 25 uses a medium access procedureor backoff procedure to determine when to transmit the resource requestMPDU 1402. In an embodiment, the backoff procedure is an enhanceddistributed channel access (EDCA) backoff procedure (e.g., shared withsingle user EDCA traffic). In an embodiment, the backoff procedure is abackoff procedure specific to OFDMA. After a suitable backoff period1404, the client station 25 transmits the resource request MPDU 1402 tothe access point 14. In an embodiment, the client station 25 transmitsthe resource request MPDU 1402 via allocated or assigned radioresources, for example, an allocated sub-channel of an OFDMcommunication channel. In an embodiment, the access point 14 generatesand transmits an acknowledgment frame 1406 in response to a successfulreceipt of the resource request MPDU 1402.

FIG. 15 is a diagram of a sequence 1500 of OFDM data units for providingbuffer information and data to an access point, according to anembodiment. In the sequence 1500, a client station 25 generates aresource request MPDU 1502. In an embodiment, the resource request MPDU1502 is similar to the MPDU 800 or MPDU 900. In the embodiment shown inFIG. 15, the client station 25 includes a wrapped MPDU within the framebody 816, as described above with respect to FIG. 8 and FIG. 9. Theclient station 25 transmits the resource request MPDU 1502 after abackoff period 1504, in a similar manner as described above with respectto FIG. 14. In an embodiment, the access point 14 generates andtransmits an acknowledgment frame 1506 in response to a successfulreceipt of the resource request MPDU 1502. In an embodiment, theacknowledgment frame 1506 is a block acknowledgment for the bufferinformation and the wrapped MPDU.

FIG. 16 is a diagram of a sequence 1600 of OFDM data units for providingbuffer information and an acknowledgment to an access point, accordingto an embodiment. In the sequence 1600, a client station 25 receives adata MPDU 1602. In an embodiment, the client station 25 generates andtransmits a resource request MPDU 1606 in response to a successfulreceipt of the data MPDU 1602. In an embodiment, the resource requestMPDU 1606 is similar to the MPDU 800 or MPDU 900. In the embodimentshown in FIG. 16, the client station 25 includes a wrapped MPDU withinthe frame body 816, as described above with respect to FIG. 8 and FIG.9. In the embodiment shown in FIG. 16, the wrapped MPDU within the framebody 816 is an acknowledgment control frame that indicates whether thedata MPDU 1602 was successfully received. In an embodiment, the clientstation 25 transmits the resource request MPDU 1606 via allocated orassigned radio resources, for example, an allocated sub-channel of anOFDM communication channel.

FIG. 17 is a diagram of a sequence 1700 of an OFDMA frame exchange foran access point that requests buffer information from multiple stations,according to an embodiment. The sequence 1700 includes downlink OFDMAdata units 1702, 1706, and 1710, which are transmitted by the AP 14 tomultiple client stations 25 (e.g., client stations STA0, STA1, STA2, andSTA3), and also includes uplink OFDMA data units 1704 and 1708, whichare transmitted by at least some of the multiple client stations to theAP 14 in response to the downlink OFDMA data units 1702 and 1706, in anembodiment.

In an embodiment, the OFDMA data unit 1702 corresponds to a schedulingframe (SYNC) for the multiple client stations STA0, STA1, STA2, andSTA3. In an embodiment, the scheduling frame is a resource allocationmessage that i) indicates an allocation of sub-channels to each of themultiple client stations, and ii) requests buffer information from themultiple client stations. In response to the scheduling frame, each ofthe multiple client stations STA0, STA1, STA2, and STA3 transmits anOFDM data unit 1704-1, 1704-2, 1704-3, and 1704-4, respectively, viasub-channels indicated in the scheduling frame. In an embodiment, one ormore of the OFDM data units 1704-1, 1704-2, 1704-3, and 1704-4 includethe MPDU 800 or MPDU 900. For example, the OFDMA data unit 1704 providesbuffer information from the multiple client stations 25 to the accesspoint 14. In an embodiment, the AP 14 allocates the sub-channels to theclient stations STA0, STA1, and STA2 and indicates a PPDU length for theOFDMA data unit 1704 that allows for only a QoS null MPDU (i.e., theMPDU 800 or the MPDU 900 with an omitted frame body).

The AP 14 determines a radio resource allocation based on the bufferinformation from the multiple client stations and generates a schedulingframe. In the embodiment shown in FIG. 17, the AP 14 generates andtransmits the OFDMA data unit 1706, which corresponds to a schedulingframe (SYNC) for the client stations STA0, STA1, and STA2. In anembodiment, the scheduling frame is a resource allocation message thatindicates an allocation of sub-channels to the client stations STA0,STA1, and STA2. In response to the scheduling frame, the client stationsSTA0, STA1, and STA2 transmit data A-MPDUs within OFDM data units1708-1, 1708-2, and 1708-3, respectively, via sub-channels indicated inthe OFDMA data unit 1706. The AP 14 transmits the OFDMA data unit 1710in response to the OFDMA data unit 1708 to acknowledge receipt, in anembodiment. In an embodiment, for example, the AP 14 generates the OFDMAdata unit 1710 to include a block acknowledgement for each of the clientstations STA0, STA2, and STA3.

FIG. 18 is a diagram of a sequence 1800 of an OFDMA frame exchange foran access point that requests buffer information from multiple stations,according to another embodiment. The sequence 1800 includes downlinkOFDMA data units 1802, 1806, and 1810, which are transmitted by the AP14 to multiple client stations 25 (e.g., client stations STA0, STA1, andSTA2), and also includes uplink OFDMA data units 1804 and 1808, whichare transmitted by at least some of the multiple client stations to theAP 14 in response to the downlink OFDMA data units 1802 and 1806, in anembodiment.

In an embodiment, the OFDMA data unit 1802 corresponds to an A-MPDU thatincludes data frames and a scheduling frame (SYNC) for the multipleclient stations STA0, STA1, and STA2. In an embodiment, the schedulingframe is a resource allocation message that requests buffer informationfrom the multiple client stations. In response to the scheduling frame,each of the multiple client stations STA0, STA1, and STA2 transmits anOFDM data unit 1804-1, 1804-2, and 1804-3, respectively, viasub-channels indicated in the scheduling frame. In an embodiment, one ormore of the OFDM data units 1804-1, 1804-2, and 1804-3 include a blockacknowledgment to the corresponding A-MPDU received from the AP 14 andone of the MPDU 800 or MPDU 900.

The AP 14 determines a radio resource allocation based on the bufferinformation from the multiple client stations and generates a schedulingframe. In the embodiment shown in FIG. 18, the AP 14 generates andtransmits the OFDMA data unit 1806, which corresponds to a schedulingframe (SYNC) for the client stations STA0, STA1, and STA2. In anembodiment, the scheduling frame is a resource allocation message thatindicates an allocation of sub-channels to the client stations STA0,STA1, and STA2. In response to the scheduling frame, the client stationsSTA0, STA1, and STA2 transmit data A-MPDUs within OFDM data units1808-1, 1808-2, and 1808-3, respectively, via sub-channels indicated inthe OFDMA data unit 1806. The AP 14 transmits the OFDMA data unit 1810in response to the OFDMA data unit 1808 to acknowledge receipt, in anembodiment. In an embodiment, for example, the AP 14 generates the OFDMAdata unit 1810 to include a block acknowledgement for each of the clientstations STA0, STA1, and STA2.

FIG. 19 is a diagram of a sequence 1900 of an OFDMA frame exchange foran access point that requests buffer information from multiple clientstations, according to yet another embodiment. The sequence 1900 issimilar to the sequence 1800, but in the embodiment of FIG. 19, the AP14 utilizes a broadcast resource information polling (RIP) frame 1902 torequest the buffer information. The broadcast RIP frame 1902 includes anassociation identifier (AID) for each of the multiple client stations,for example, in a frame body of the broadcast RIP frame 1902. In anembodiment, for example, the broadcast RIP frame 1902 includes Massociation identifiers, where M is an integer. In response to thebroadcast RIP frame 1902, each of the multiple client stations providesa respective resource request MPDU 1904-1, 1904-2, . . . 1904-M. In anembodiment, the resource request MPDU 1904 corresponds to one of theresource request MPDU 800 or 900. In the embodiment shown in FIG. 19,each of the multiple client stations responds in an order of theassociation identifiers within the broadcast RIP frame 1902. In otherembodiments, another suitable order for the resource request MPDUs 1904is utilized.

FIG. 20 is a diagram of a sequence 2000 of an OFDMA frame exchange foran access point that requests buffer information from multiple clientstations, according to another embodiment. The sequence 2000 is similarto the sequence 1800, but in the embodiment of FIG. 20, the AP 14utilizes a plurality of M unicast resource information polling (RIP)frames 2002 to request the buffer information from M client stations,where M is an integer. In an embodiment, each of the M unicast RIPframes 2002 includes an association identifier (AID) for one of theclient stations, for example, in a frame body of the unicast RIP frame2002. In response to the unicast RIP frame 2002, the correspondingclient station provides a resource request MPDU 2004. In an embodiment,the resource request MPDU 2004 corresponds to one of the resourcerequest MPDU 800 or 900. In some embodiments, the unicast RIP frame 2002omits the frame body 816.

FIG. 21 is a diagram of a sequence 2100 of an OFDMA frame exchange foran access point that requests buffer information from multiple clientstations, according to yet another embodiment. The sequence 2100 issimilar to the sequence 1800, but in the embodiment of FIG. 21, the AP14 utilizes an OFDMA data unit to provide a resource information polling(RIP) frame 2102 to request the buffer information. In an embodiment,the RIP frame 2102 includes a RIP frame that wraps a scheduling or SYNCframe, in a manner similar to the wrapped MPDU described above withrespect to FIG. 8. In this embodiment, the RIP frame 2102 includes abroadcast receiver address and the scheduling frame indicates themultiple client stations. In response to the RIP frame 2102, each of themultiple client stations indicated by the scheduling frame transmits arespective OFDM data unit 2104. In an embodiment, one or more of theOFDM data units 2104-1, 2104-2, and 2104-3 include the MPDU 800 or MPDU900. In another embodiment, the resource request is indicated in a SYNCframe, so the separate RIP frame 2102 is not needed.

FIG. 22 is a diagram of a sequence 2200 of an OFDMA exchange for abuffer information request utilizing separated polling, according to anembodiment. The sequence 2200 includes a polling TXOP 2202 and a datatransfer TXOP 2204, in an embodiment. While only one polling TXOP 2202and data transfer TXOP 2204 are shown, additional polling TXOPs areutilized prior to a data transfer TXOP 2204, or additional data transferTXOPs are utilized after polling, in various embodiments. In someembodiments, the AP 14 groups a plurality of client stations intodifferent OFDMA data units or different polling TXOPs for receiving thebuffer information. In some embodiments, the AP 14 groups a plurality ofclient stations into different OFDMA data units or different datatransmission TXOPs for receiving data transmissions from the clientstations.

In the embodiment shown in FIG. 22, the AP 14 utilizes a plurality of Mgroups, where M is an integer, and transmits a respective OFDMA dataunit 2206, including a scheduling frame, to each of the M groups torequest the buffer information from M client stations (e.g., OFDMA dataunits 2206-1, 2206-2, . . . 2206-M). In various embodiments, each of theM groups includes one, two, three, or another suitable number of clientstations. In an embodiment, each of the client stations of a same grouptransmits an OFDM data unit as part of an OFDMA data unit 2208 inresponse to the corresponding scheduling frame (e.g., OFDMA data units2208-1, 2208-2, . . . 2208-M). In the embodiment shown in FIG. 22, theAP 14 transmits a non-HT duplicate data unit or OFDMA data unit 2206-1to a first group of client stations where the non-HT duplicate data unitor OFDMA data unit 2206-1 includes the scheduling frame and, inresponse, the AP 14 receives the OFDMA data unit 2208-1 that includesresource request MPDUs (e.g., resource request MPDU 800 or 900) from thefirst group of client stations. The AP 14 repeats the transmission ofthe non-HT duplicate data unit or OFDMA data unit 2206 for each of the Mgroups and receives corresponding resource request MPDUs from the clientstations. During the data transfer TXOP 2204, the AP 14 determines aradio resource allocation based on the buffer information from themultiple client stations and generates a scheduling frame. The AP 14 andclient stations exchange UL OFDMA frame exchange shown by 2210, 2212,and 2214, in a manner similar to the exchange of OFDMA frame exchangeshown by 1806, 1808, and 1810, as described above with respect to FIG.18.

FIG. 23 is a diagram of a sequence 2300 of an OFDMA exchange for abuffer information request utilizing separated polling, according toanother embodiment. The sequence 2300 includes a polling TXOP 2302 and adata transfer TXOP 2304 that are similar to the polling TXOP 2202 anddata transfer TXOP 2204 described above with respect to FIG. 22, in anembodiment. During, the polling TXOP 2302, the AP 14 utilizes aplurality of M unicast resource information polling (RIP) frames 2304 torequest the buffer information from M client stations, where M is aninteger. In an embodiment, each of the M unicast RIP frames 2304includes an association identifier (AID) for one of the client stations,for example, in a frame body of the unicast RIP frame 2304. In responseto the unicast RIP frame 2304, the corresponding client station providesa resource request MPDU 2306. In an embodiment, the resource requestMPDU 2306 corresponds to one of the resource request MPDU 800 or 900. Insome embodiments, the unicast RIP frame 2304 omits the frame body 816.

FIG. 24 is a diagram of a sequence 2400 of an OFDMA exchange for abuffer information request within a restricted access window, accordingto an embodiment. The sequence 2400 includes a restricted access window2402 and a data transfer TXOP 2404. The data transfer TXOP 2404 issimilar to the data transfer TXOP 2304, described above with respect toFIG. 23, in an embodiment. An example of a restricted access window isdescribed in IEEE Draft Standard for Information Technology, Part 11:Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)Specifications, Amendment 6: Sub 1 GHz License Exempt Operation, 2013(“the IEEE 802.11ah standard”), the disclosure of which is incorporatedherein by reference in its entirety. In an embodiment, for example, therestricted access window 2402 is divided into one or more time slots andthe AP 14 assigns to each of the multiple client stations (or a group ofclient stations) a time slot, inside which the client stations areallowed to contend for medium access. During a time slot, a clientstation 25 contends for medium access by waiting for a suitable backoffperiod (e.g., similar to backoff period 1404), then exchanges a resourcerequest MPDU 2406 and acknowledgment 2408 with the access point 14, in amanner similar to the resource request MPDU 1402 and acknowledgment1406, described above with respect to FIG. 14.

FIG. 25 is a diagram of a quality of service (QoS) control field 2500 ofan MPDU (not shown) that includes a scale factor for buffer information,according to an embodiment. In an embodiment, the MPDU is similar to theMPDU 700, but the QoS control field 2500 replaces the QoS control field714. The QoS control field 2500 is based on the QoS control field for aQoS data frame and includes a traffic identifier (TID) subfield 2502(bits 0-3), a zero subfield 2504 (bit 4), an acknowledgment policysubfield 2506 (bits 5-6), an A-MSDU present subfield 1508 (bit 7), and aresource request subfield 2510 (8 bits). The resource request subfield2510 includes a scale factor subfield 2512 and a resource subfield 2514.In an embodiment, the scale factor subfield 2512 and resource subfield2514 are similar to the scale factor subfield 822 and resource subfield824, as described above with respect to FIG. 8.

FIG. 26 is a diagram of a resource request MPDU 2600 that includesbuffer information for a resource request, according to an embodiment.The resource request MPDU 2600 includes the frame control field 804 (2octets), the first address (A1) field 810-1 (6 octets), the secondaddress (A2) field 810-2 (6 octets), the duration field (2 octets) 812,and a resource request field 2602 (2 octets), in an embodiment. In theembodiment shown in FIG. 26, the frame body 816 is omitted (e.g., a nulldata frame). The resource request field 2602 includes i) a resource typesubfield 2604 that indicates whether the buffer information indicatesthe number of bytes or the TXOP duration, ii) a scale factor subfield2606 that indicates a scale value, and iii) a resource subfield 2608 (orbuffer information indication) that indicates a base resource value. Thescale factor subfield 2606 and the resource subfield 2608 are similar tothe scale factor subfield 822 and resource subfield 824, respectively,as described above with respect to FIG. 8.

FIG. 27 is a diagram of a resource request field 2700 that includesbuffer information for multiple resource requests, according to anotherembodiment. In an embodiment, for example, the resource request field2700 replaces the resource request field 2602 of the resource requestMPDU 2600. In the illustrated embodiment, the resource request field2700 includes a bitmap subfield 2702 and a resource subfield 2703. Inother embodiments, the resource request field 2700 includes a pluralityof instances (not shown) of the resource subfield 2703. In anembodiment, for example, the bitmap subfield 2702 is similar to thebitmap subfield 904 (described above with respect to FIG. 9) andindicates which data groups of a plurality of data groups correspond toa resource subfield included in the resource request field 2700. Theresource subfield 2703 includes i) a resource type subfield 2704 thatindicates whether the buffer information indicates the number of bytesor the TXOP duration, ii) a scale factor subfield 2706 that indicates ascale value, and iii) a resource subfield 2708 (or buffer informationindication) that indicates a base resource value. The scale factorsubfield 2706 and the resource subfield 2708 are similar to the scalefactor subfield 822 and resource subfield 824, respectively, asdescribed above with respect to FIG. 8.

FIG. 28 is a flow diagram illustrating an example method 2800 fortransmitting a resource request for an OFDMA transmission, according toan embodiment. In an embodiment, the method 2800 is implemented by aclient station in the WLAN, according to an embodiment. With referenceto FIG. 1, the method 2800 is implemented by the network interface 27,in an embodiment. For example, in one such embodiment, the PHY processor29 is configured to implement the method 2800. According to anotherembodiment, the MAC processing 28 is also configured to implement atleast a part of the method 2800. With continued reference to FIG. 1, inyet another embodiment, the method 2800 is implemented by the networkinterface 16 (e.g., the PHY processor 20 and/or the MAC processor 18).In other embodiments, the method 2800 is implemented by other suitablenetwork interfaces.

At block 2802, a resource request field is generated by a firstcommunication device. In an embodiment, the resource request fieldindicates buffer information corresponding to queued media accesscontrol (MAC) protocol data units (MPDUs) that are queued fortransmission by the first communication device. The resource requestfield includes i) a scale factor subfield that indicates a scale value,and ii) a resource subfield that indicates a base resource value, in anembodiment. The buffer information is i) a number of bytes indicated bythe scale value multiplied by the base resource value, or ii) atransmission opportunity (TXOP) duration indicated by the scale valuemultiplied by the base resource value, in an embodiment. In anembodiment, the resource request field indicates whether the bufferinformation indicates the number of bytes or the TXOP duration.

In an embodiment, the resource request field includes a bitmap subfieldthat indicates which data groups of a plurality of data groupscorrespond to a resource subfield included in the resource requestfield. In an embodiment, the bitmap subfield includes a bit for each ofthe plurality of data groups and the resource request field includes arespective resource subfield for each data group indicated by the bitmapsubfield. In an embodiment, the data groups are i) traffic classes, orii) access categories. In an embodiment, each of the respective resourcesubfields indicates whether the buffer information for the correspondingdata group indicates the number of bytes or the TXOP duration. In anembodiment, the buffer information corresponds to a total number ofqueued MPDUs for a plurality of data groups.

In an embodiment, a wrapped MPDU field is generated that includes i) awrapped type subfield that indicates a frame type of a wrapped MPDU, andii) a wrapped payload subfield that includes a payload for the wrappedMPDU. In this embodiment, a wrapper subfield is generated that indicatesthat the wrapped MPDU is included in the resource request MPDU, and theresource request MPDU is generated to include the resource request fieldand the wrapped MPDU. In this embodiment, the resource request MPDU isgenerated to include the resource request field and the wrapped MPDU. Inan embodiment, the resource request MPDU includes a frame type subfieldthat indicates a frame type of the resource request MPDU, and the frametype of the wrapped MPDU is different from the frame type of theresource request MPDU. In an embodiment, the buffer informationcorresponds to a first data group and the wrapped MPDU corresponds to asecond data group that is different from the first data group.

In an embodiment, the resource request information is in an HT variantHT Control field with a reserved bit in the HT variant Control field setto a value of 1 or other suitable value to indicate that the HT variantHT Control field includes the resource request information. In anembodiment, the resource request information is in a VHT variant Controlfield with a reserved bit in the VHT variant HT Control field set to avalue of 1 or other suitable value to indicate that the VHT variant HTControl field includes the resource request information.

At block 2804, a resource request MPDU is generated that includes theresource request field by the first communication device.

At block 2806, the resource request MPDU is transmitted by the firstcommunication device to a second communication device to request anallocation of radio resources for the OFDMA transmission by the secondcommunication device. In an embodiment, the resource request MPDU isencapsulated in a PHY header by the PHY processor 20 or the PHYprocessor 29 prior to transmission.

In some embodiments, the first communication device receives a pollingframe from the second communication device and generates the resourcerequest MPDU in response to the polling frame. In an embodiment, theresource request field is a Quality of Service (QoS) control field andthe resource request MPDU is a first QoS null MPDU. In an embodiment, anaggregate MPDU (A-MPDU) is generated by the first communication device.The A-MPDU includes the first QoS null MPDU and at least one other MPDU.In an embodiment, the at least one other MPDU includes a second QoS nullMPDU. In this embodiment, the first QoS null MPDU corresponds to a firstdata group and the second QoS null MPDU corresponds to a second datagroup that is different from the first data group.

FIG. 29 is a flow diagram illustrating an example method for allocatingradio resources for an OFDMA transmission, according to anotherembodiment. In an embodiment, the method 2900 is implemented by anaccess point in the WLAN, according to an embodiment. With reference toFIG. 1, the method 2900 is implemented by the network interface 27, inan embodiment. For example, in one such embodiment, the PHY processor 29is configured to implement the method 2900. According to anotherembodiment, the MAC processing 28 is also configured to implement atleast a part of the method 2900. With continued reference to FIG. 1, inyet another embodiment, the method 2900 is implemented by the networkinterface 16 (e.g., the PHY processor 20 and/or the MAC processor 18).In other embodiments, the method 2900 is implemented by other suitablenetwork interfaces.

At block 2902, a resource request media access control (MAC) protocoldata unit (MPDU) is received from a second communication device. In anembodiment, the resource request MPDU includes a resource request fieldthat indicates buffer information corresponding to queued MPDUs that arequeued for transmission by the second communication device. In anembodiment, the resource request field includes i) a scale factorsubfield that indicates a scale value, and ii) a resource subfield thatindicates a base resource value. In an embodiment, the resource requestfield is a Quality of Service (QoS) control field and the resourcerequest MPDU is a first QoS null MPDU. In an embodiment, the resourcerequest field is an HT variant HT Control field with a reserved bit inthe HT variant HT Control field set to a value of 1 (or other suitablevalue) to indicate the resource request information. In anotherembodiment, the resource request field is a VHT variant HT Control fieldwith a reserved bit in the VHT variant HT Control field set to a valueof 1 (or other suitable value) to indicate the resource requestinformation.

In an embodiment, the resource request field includes a bitmap subfieldthat indicates which data groups of a plurality of data groupscorrespond to a resource subfield included in the resource requestfield. In an embodiment, the bitmap subfield includes a bit for each ofthe plurality of data groups and the resource request field includes arespective resource subfield for each data group indicated by the bitmapsubfield. In an embodiment, the first communication device determinesthe radio resources by multiplying the scale value by the base resourcevalue.

In an embodiment, receiving the resource request MPDU includes receivingan aggregate MPDU (A-MPDU) that includes the first QoS null MPDU and atleast one second QoS null MPDU. In this embodiment, generating thescheduling MPDU includes generating the scheduling MPDU to include anacknowledgment for the A-MPDU if at least one of the first QoS null MPDUor the at least one second QoS null MPDU has been correctly received.

At block 2904, radio resources are allocated by the first communicationdevice to the second communication device for the OFDMA transmissionbased on the scale value and the base resource value.

At block 2906, a scheduling MPDU that indicates the radio resourcesallocated to the second communication device is generated by the firstcommunication device.

At block 2908, the scheduling MPDU is transmitted by the firstcommunication device to the second communication device. In anembodiment, the resource request MPDU is encapsulated in a PHY header bythe PHY processor 20 or the PHY processor 29 prior to transmission.

At least some of the various blocks, operations, and techniquesdescribed above may be implemented utilizing hardware, a processorexecuting firmware instructions, a processor executing softwareinstructions, or any combination thereof. When implemented utilizing aprocessor executing software or firmware instructions, the software orfirmware instructions may be stored in any computer readable memory suchas on a magnetic disk, an optical disk, or other storage medium, in aRAM or ROM or flash memory, processor, hard disk drive, optical diskdrive, tape drive, etc. The software or firmware instructions mayinclude machine readable instructions that, when executed by one or moreprocessors, cause the one or more processors to perform various acts.

When implemented in hardware, the hardware may comprise one or more ofdiscrete components, an integrated circuit, an application-specificintegrated circuit (ASIC), a programmable logic device (PLD), etc.

While the present invention has been described with reference tospecific examples, which are intended to be illustrative only and not tobe limiting of the invention, changes, additions and/or deletions may bemade to the disclosed embodiments without departing from the scope ofthe invention.

What is claimed is:
 1. A method for transmitting a resource request foran orthogonal frequency division multiple access (OFDMA) transmission,the method comprising: generating, by a first communication device, aresource request field that indicates buffer information correspondingto queued media access control (MAC) protocol data units (MPDUs) thatare queued for transmission by the first communication device, theresource request field including i) a scale factor subfield thatindicates a scale value, and ii) a resource subfield that indicates abase resource value; generating, by the first communication device, aresource request MPDU that includes the resource request field; andtransmitting, by the first communication device, the resource requestMPDU to a second communication device via a wireless communicationchannel to request an allocation of radio resources for the OFDMAtransmission by the second communication device; wherein the bufferinformation is i) a number of bytes indicated by the scale valuemultiplied by the base resource value, or ii) a transmission opportunity(TXOP) duration indicated by the scale value multiplied by the baseresource value.
 2. The method of claim 1, wherein the resource requestfield includes: a bitmap subfield that indicates which data groups of aplurality of data groups correspond to a resource subfield included inthe resource request field, the bitmap subfield including a bit for eachof the plurality of data groups, and a respective resource subfield foreach data group indicated by the bitmap subfield.
 3. The method of claim2, wherein the data groups are i) traffic classes, or ii) accesscategories.
 4. The method of claim 2, wherein each of the respectiveresource subfields indicates whether the buffer information for thecorresponding data group indicates the number of bytes or the TXOPduration.
 5. The method of claim 1, wherein the buffer informationcorresponds to a total number of queued MPDUs for a plurality of datagroups.
 6. The method of claim 1, further comprising: generating awrapped MPDU field that includes i) a wrapped type subfield thatindicates a frame type of a wrapped MPDU, and ii) a wrapped payloadsubfield that includes a payload for the wrapped MPDU; wherein:generating the resource request field comprises generating a wrappersubfield indicating that the wrapped MPDU is included in the resourcerequest MPDU, and generating the resource request MPDU includesgenerating the resource request MPDU to include the resource requestfield and the wrapped payload.
 7. The method of claim 6, wherein: theresource request MPDU includes a frame type subfield that indicates aframe type of the resource request MPDU, and the frame type of thewrapped MPDU is different from the frame type of the resource requestMPDU.
 8. The method of claim 6, wherein the buffer informationcorresponds to a first data group and the wrapped MPDU corresponds to asecond data group that is different from the first data group.
 9. Themethod of claim 1, further comprising receiving a polling frame from thesecond communication device; wherein the first communication devicegenerates the resource request MPDU in response to the polling frame.10. The method of claim 1, wherein the resource request field indicateswhether the buffer information indicates the number of bytes or the TXOPduration.
 11. The method of claim 1, wherein the resource request fieldis a high throughput (HT) variant HT Control field with one reserved bitin the HT variant HT Control field set to a value of
 1. 12. The methodof claim 1, wherein the resource request field is a very high throughput(VHT) variant HT Control field with one reserved bit in VHT variant HTControl field set to a value of
 1. 13. The method of claim 1, whereinthe resource request field is a Quality of Service (QoS) control fieldand the resource request MPDU is a first QoS null MPDU.
 14. The methodof claim 13, further comprising generating an aggregate MPDU (A-MPDU)that includes the first QoS null MPDU and at least one other MPDU;wherein transmitting the resource request MPDU comprises transmittingthe A-MPDU to the second communication device.
 15. The method of claim13, wherein: the at least one other MPDU includes a second QoS nullMPDU, and the first QoS null MPDU corresponds to a first data group andthe second QoS null MPDU corresponds to a second data group that isdifferent from the first data group.
 16. A first communication devicethat transmits a resource request for an orthogonal frequency divisionmultiple access (OFDMA) transmission, comprising: a network interfacedevice having one or more integrated circuits configured to generate aresource request field that indicates buffer information correspondingto queued media access control (MAC) protocol data units (MPDUs) thatare queued for transmission by the first communication device, theresource request field including i) a scale factor subfield thatindicates a scale value, and ii) a resource subfield that indicates abase resource value, generate a resource request MPDU that includes theresource request field, and transmit the resource request MPDU to asecond communication device via a wireless communication channel torequest an allocation of radio resources for the OFDMA transmission bythe second communication device; wherein the buffer information is i) anumber of bytes indicated by the scale value multiplied by the baseresource value, or ii) a transmission opportunity (TXOP) durationindicated by the scale value multiplied by the base resource value. 17.The first communication device of claim 16, wherein the resource requestfield includes: a bitmap subfield that indicates which data groups of aplurality of data groups correspond to a resource subfield included inthe resource request field, the bitmap subfield including a bit for eachof the plurality of data groups; and a respective resource subfield foreach data group indicated by the bitmap subfield.
 18. The firstcommunication device of claim 17, wherein each of the respectiveresource subfields indicates whether the buffer information for thecorresponding data group indicates the number of bytes or the TXOPduration.
 19. The first communication device of claim 16, wherein theone or more integrated circuits are configured to: generate a wrappedMPDU field that includes i) a wrapped type subfield that indicates aframe type of wrapped MPDU, and ii) a wrapped payload subfield thatincludes a payload for the wrapped MPDU; generate a wrapper subfieldindicating that the wrapped MPDU is included in the resource requestMPDU; and generate the resource request MPDU to include the resourcerequest field and the wrapped MPDU.
 20. A method for allocating radioresources for an orthogonal frequency division multiple access (OFDMA)transmission, the method comprising: receiving, by a first communicationdevice, a resource request media access control (MAC) protocol data unit(MPDU) from a second communication device, wherein the resource requestMPDU includes a resource request field that indicates buffer informationcorresponding to queued MPDUs that are queued for transmission by thesecond communication device, the resource request field including i) ascale factor subfield that indicates a scale value, and ii) a resourcesubfield that indicates a base resource value; allocating, by the firstcommunication device, radio resources to the second communication devicefor the OFDMA transmission based on the scale value and the baseresource value; generating, by the first communication device, ascheduling MPDU that indicates the radio resources allocated to thesecond communication device; and transmitting, by the firstcommunication device, the scheduling MPDU to the second communicationdevice via a wireless communication channel.
 21. The method of claim 20,wherein the resource request field includes: a bitmap subfield thatindicates which data groups of a plurality of data groups correspond toa resource subfield included in the resource request field, the bitmapsubfield including a bit for each of the plurality of data groups; and arespective resource subfield for each data group indicated by the bitmapsubfield; wherein the method further comprises determining the radioresources by multiplying the scale value by the base resource value. 22.The method of claim 20, wherein the resource request field is a Qualityof Service (QoS) control field and the resource request MPDU is a firstQoS null MPDU.
 23. The method of claim 22, wherein: receiving theresource request MPDU comprises receiving an aggregate MPDU (A-MPDU)that includes the first QoS null MPDU and at least one second QoS nullMPDU; and generating the scheduling MPDU comprises generating thescheduling MPDU to include an acknowledgment for the A-MPDU if at leastone of the first QoS null MPDU or the at least one second QoS null MPDUhas been correctly received.
 24. A first communication device thatallocates radio resources for an orthogonal frequency division multipleaccess (OFDMA) transmission, comprising: a network interface devicehaving one or more integrated circuits configured to receive a resourcerequest media access control (MAC) protocol data unit (MPDU) from asecond communication device, wherein the resource request MPDU includesa resource request field that indicates buffer information correspondingto queued MPDUs that are queued for transmission by the secondcommunication device, the resource request field including i) a scalefactor subfield that indicates a scale value, and ii) a resourcesubfield that indicates a base resource value, allocate radio resourcesto the second communication device for the OFDMA transmission based onthe scale value and the base resource value, generate a scheduling MPDUthat indicates the radio resources allocated to the second communicationdevice, and transmit the scheduling MPDU to the second communicationdevice via a wireless communication channel.
 25. The first communicationdevice of claim 24, wherein the resource request field includes: abitmap subfield that indicates which data groups of a plurality of datagroups correspond to a resource subfield included in the resourcerequest field, the bitmap subfield including a bit for each of theplurality of data groups; and a respective resource subfield for eachdata group indicated by the bitmap subfield; wherein the one or moreintegrated circuits are configured to determine the radio resources bymultiplying the scale value by the base resource value.
 26. The firstcommunication device of claim 24, wherein the resource request field isa Quality of Service (QoS) control field and the resource request MPDUis a first QoS null MPDU.